Color photographic silver halide emulsion containing magenta couplers

ABSTRACT

A COLOR PHOTOGRAPHIC SILVER HALIDE EMULSION CONTAINING 1-ARYL-5-(M-ACYLAMINOPHENYLUREIDO)-5-PYRAZOLONE AS A MAGENTA COUPLER WHEREIN THE ACYL GROUP HAS 18 TO 25 CARBON ATOMS AND THE ARYL GROUP HAS AT LEAST ONE SUBSTITUENT AT THE ORTHO POSITION, THE SUBSTITUENT BEING CHOSEN FROM THE CLASS CONSISTING OF HALOGENS, ALKYL GROUPS AND ALKOXYL GROUPS.

United States Patent O 3,558,319 COLOR PHOTOGRAPHIC SILVER HALIDE EMUL-SION CONTAINING MAGENTA COUPLERS Tsutomu Hamaoka, Kazuya Sano, MakotoYoshida, Yasushi Oishi, and Takeshi Hrose, Kanagawa, Japan, assignors toFuji Shashin Film Kabushiki Kasha, Kanagawa, Japan Filed July 12, 1967,Ser. No. 652,891 Claims priority, application Japan, July 13, 1966, 41/45,814 Int. Cl. G03c 1/40 U.S. Cl. 96--100 14 Claims ABSTRACT F THEDISCLOSURE A color photographic silver halide emulsion containing laryl-3-(m-acylaminophenylureido)-S-pyrazolone as a magenta couplerwherein the acyl group has 18 to 25 carbon atoms and the aryl group hasat least one substituent at the ortho position, the substituent beingchosen from the class consisting of halogens, alkyl groups and alkoxylgroups.

BACKGROUND OF THE INVENTION l) Field of the invention The presentinvention relates to color photography, and particularly to colorphotographic materials containing -pyrazolone couplers that carryortho-substituted phenyl groups at position 1 andm-acylaminophenyl-ureido groups at position 3 of the pyraziolone nuclei.

(2) yDescription of the prior art In the conventional substractive colorphotographic process, the magenta-colored image is produced by theoxidative coupling of a 5-pyrazolone and a p-phenylenediamine, inparticular an N,Ndalkylp-phenylene (ortolylene-l-diamine. The magnetaimage contributes greenlight absorption on the spectral region of 500 to600 mp.. It is desired thatthe extinction be large in this region andsmall outside of this region, that is, in the blue and red regions. Theazomethine dye derived from a pyrazolone coupler, however, has a secondA.absorption maximum around 440 ma, together with the main absorptionmaximum near 550 The former is a serious obstruction to desirable colorproduction of the blue color. This has led to many attempts to sol-vethe problem, and U.S. Pat. No. 2,369,489, which relates to ya3-acylamino-5-pyrazolone, has brought about a considerable but by uomeans quite satisfactory improvement.

Another requirement for desirable color reproduction is that theextinction rapidly drops toward the longer wave lengths. As a matter offact, the extinction of the pyrazolone azomethine dyes extends over 600ma, resulting in an undesirable red light absorption. On the other hand,a simple trial of narrowing the absorption range will be accompanied bythe reduction of the whole green absorption. In order to express theabsorption characteristics as have been mentioned, the followingformulas are often used:

Wvalue=Halfvalue width=distance between k max and the wave-length wherethe extinction is half as great as that at main absorption maximumS-value Thus, it is an object of this invention to provide couplers thatyield dyes with small B- and S-Values and with a not too small W-value.

In addition, the coupler must have a sufficient coupling activity towardp-phenylenediamine developers in order that the exposed photographicemulsion show high sensitively and high gradation and rapid development.It has hitherto been known that 1-aryl-3-acylamino-S-pyrazolone couplersprovide fairly good absorption characteristics, while their couplingactivities are usually low and hardly yield enough color density. On thecontrary, the use of a coupler with excessively high coupling activityleads to color images of poor quality and increased fog. Thus, it isanother object of this invention to provide color couplers that haveenough, but not excessive, coupling activity.

A third requirement of the couplers relates to the fastness of the dyederived therefrom. The magenta color image produced through conventionalcolor development has a tendency to fade or discolor when exposed tolight, heat or humidity. In addition, the coupler that has survived thedevelopment process is apt to form yellow stains during storage. Thus,it is a third object of this i11- vention to provide color couplers thatare themselves resistant to light and which also form dyes Iwhich areresistant to light.

The following three methods have been employed t0 incorporatediffusion-resistant couplers into the emulsion layers of multi-layermaterials.

(l) Into an emulsion is added a coupler which has been dissolved in anaqueous alkali with the aid of a carboxylic or a sulfonic acid groupwhich the coupler carries. The emulsion can be neutralized, ifnecessary.

(2) A coupler is dissolved in an organic solvent and the solution isdispersed in an aqueous medium to form ne colloidal particles, beforebeing added into the photographic emulsion, and

(3) A coupler melt is directly dispersed into a photographic emulsion oris dispersed in an aqueous medium before being added to the emulsion. Ofthe foregoing processes, the second process has been known to givebetter absorption characteristics and faster image dyes. In this casethe coupler is dissolved in the smallest possible amount of solvent tosecure a high level of photographic properties in the emulsion, highquality of the dye image, and good mechanical properties of the emulsionlayers. This necessarily requires a high solubility of the coupler inthe solvent in question. As a whole, 1aryl3arylureido S-pyrazolone isnot very easily soluble in such non-polar solvents as are conventionallyused, lalthough it has excellent absorption characteristics. Therefore,it is a fourth object of this invention to provide easily solublel-phenyl- 3-aryl-ureido-S-pyrazolones.

SUMMARY OF TH-E INVENTION The inventors have found that the compound ofthe following general formula satisfies -all the requirements mentionedabove:

I Ar

wherein RCO represents an acyl group having 18 to 25 carbon atoms and Arrepresents a phenyl group having at least one substituent lat the orthoposition, the suhstituent being chosen from the class consisting ofhalogens, lower alkyl groups and lower alkoxy groups.

The RCO group contributes the solubility of the coupler as well as itsresistance to ditusion. If the RCO group carries less than 18 carbonatoms, the coupler wanders out of the layer because of the lowsolubility in the organic solvent and low diffusion-resistance,resulting in a worsened color reproduction. On the other hand, anexcessively large RCO group, having more than 25 carbon atoms, bringsabout an excessively large molecular weight and thus too small anextinction per volume. Moreover the dispersion force due to this part ofthe molecule reduces the solubility of the coupler. The RCO group ismost suitably located meta to the ureido group since the compound ofthis location provides a higher solubility than its isomers. Forexample, the para isomer gives the dye of the absorption characteristicsas excellent as the meta isomer but cannot be employed owing to its lowsolubility. This feature is well illustrated in Table 1.

The RCO group is preferably a substituted or an unsubstituted aliphaticacyl group or one of the following:

(a) -o o cHoQ-R, (b) o o ono@ wherein R1 represents a hydrogen atom oran alkyl group having not more than 3 carbon atoms, R2 represents analkyl group having not more than carbon atoms, R3 represents an alkylgroup having from 5 to 16 carbon atoms, and n is an integer from 1 to 5.

The ortho substituent of the Ar group is quite important because thelack of the substituent gives rise to too low a solubility, and anexcessive coupling activity, which leads to fogging, and thus, toworsening of the image quality.

The elfect of the ortho substituent is believed to be due to loss of theco-planarity of the pyrazolone and the aryl nuclei, which are affectedby many kinds of substituents, such as halogens, alkyl groups andalkoxyl groups. These substituents are also effective in preventing theyellowing of the couplers by light. In particular, those that carry twosubstituents at the ortho positions are remarkably resistant to theaction of light.

BRIEF DESCRIPTION OF THE DRAWING FIGS. 1, 2 and 3 show the spectralabsorption curves of dye images obtained by processing couplers I, IVand 1X with 2-amino-5-diethylaminotoluene compared with those from thecorresponding reference couplers. Curves a and b of FIG. 1, c and d ofFIG. 2 and e and f of FIG. 3 correspond to couplers I, A, 1V, B, IX andH, respectively.

DETAILED DESCRIPTION OF THE INVENTION The couplers suitably used in thepresent invention are exemplified by the following:

(II) sec. cmu-@ocmooNH-Q 5 slee. 05H11 NHcoNH-(I-Iom N\ c=o ClsHaiCONoHzcHzcoNH- 04H9 NHooNH-ccnl N\ c=o N t I (1V) terecnu -OCHQCONEQtermali NHcoNH-c--C'm N c=o cic1 sec. 05H

tert. 05H11 NHCONH-l-ICHz (VII) OHzCHaCONH- (VIII) (IJzHs tel'iLCsHu *OCHCONH- I tert. 05H11 l NEC ONH-C- CHz l tert. 05H11 l tert. 05H11 (XII)30 Each of the following compounds has Someting in common with couplersI-XIII. Comparison of the two groups will serve to illustrate the meritsof the couplers of the present invention.

sec.CiHu

tert. H11

teraom- -ooHcroNH tert. 05H11 (n @-s olNH-Il-cm, No N\ /c=o The magentacolor image obtained from the color photographic material containing thecoupler of this invention fades only reluctantly by the action of light,heat and environmental humidity, as is shown in Example 4, and theremaining coupler scarcely yellows when exposed to strong radiation.This makes this invention especially valuable from the viewpoint ofimage preservation.

In the second place, the coupler of this invention gives highsensitivity and desirable gradation to the photographic emulsion, whilegiving rise to little fogging owing to its moderate couplng activity. Inaddtion, the present coupler shows a high rate of conversion toazomethine dyes and thus increases the sensitivity even more. Thisresults in a smaller amount of coupler needed, and thus, in a thinneremulsion layer, which improves the image quality and the rate ofdevelopment.

Thirdly, the coupler of this invention has a high solubility in suchorganic solvents as di-n-butyl phthalate and ethyl acetate. In otherwords, only a small amount of solvent is needed to disperse this kind ofcoupler. This necessarily simplifies the production of the photographicmaterial. `It also excludes the need for a thick layer, guaranteeinghigher quality of the image, a higher development' rate, and bettermechanical properties of the emulsion layer. Table 1 shows thesolubilities and melting points of couplers I, V, IX and X, togetherwith those of reference couplers C.1D.F. and B, which have structuressimilar to couplers I, V, IX and X, respectively. The solubility hasbeen designated as the amount of ethyl acetate needed to dissolve 1 partof the coupler at 60 C. It should be noted that a smaller valuecorresponds to a higher solubility.

TABLE I.-MELTING POINTS AND SOLUBILITIES OF THE COUPLE RS OF THISINVENTION COMPARED WITH THE REFERENCE COUPLERS t Solubility (definedabove) 2.5 2.0 1.5 1.0 7.5 7.5 7.5 2.0

In the fourth place, dyes from the couplers of this invention giveabsorption characteristics suited for the subtractive color process.

Referring to the drawing, all the figures indicate that the couplers ofthe present invention, which carry 3-(macylaminophenyl-ureido)substitutents are superior to the reference couplers of known types,which carry 3-acylamino substituents, especially with regard to theabsorption in the shorter waive-length region.

Such excellent absorption characteristics are believed to be due notonly to the high solubility of the dyes in the co-existing solvent, butalso to their own nature.

Table 2 illustrates the absorption characteristics of ethyl acetate ofdyes obtained by the oxidative coupling of the couplers of thisinvention with 2amino5-N,Ndi ethylaminotoluene along with those from thecorresponding reference couplers.

Couplers of the invention Reference couplers I V A B E G J K Primaryabsorption max. wave length (mit) 534 541 525 535 537 519 541 539Secondary absorption max. wave length (mp 433 431 441 438 435 445 431438 B-value 0. 14 0. 13 0. 21 0. 17 0. l6 0. 46 0. 17 0. 17 W-value(mit) 74 76 79 78 75 78 79 80 S-value 0. 2l 0. 19 0. 26 0. 22 0 29 0. 350. 24 0. 24

It will be clearly seen that the couplers of the present invention areespecially suited for color photography because of unusually small B-(second absorption) and S-(red absorption) values while maintainingmoderate W-values.

The following exemplify the preparation of these compounds:

Preparation of Compound I (a) Preparation of m-nitrophenyl isocyanate-Ina 5- liter three-necked flask were placed 500 m1. of ethyl acetate,saturated with phosgene at room temperature. While refluxing and passingphosgene, 150 g. of m-nitroaniline, dissolved in 1.5 liters of dry ethylacetate were gradually added. After addition of m-nitroaniline over 4hours at such a rate as to avoid accumulation of nitronanilinehydrochloride, phosgene was passed in for 5 minutes more, ethyl acetateWas distilled out, and the viscous residue was distilled under reducedpressure by means of an aspirator. AOne hundred and thirty grams ofm-nitrophenyl isocyanate boiling at 161 C./ 25 mm. Hg was obtained.

(b) Synthesis of l-(2-chlorophenyl)-3-(3-nitrophenylureido)5pyrazolone.-In a 1 liter three-necked flask were placed 76 g. of1-(2-chlorophenyl)3 amino-S-pyrazolone (I. Am. Chem. Soc., 66 18612(1944)) and 600 m1. of acetonitrile. While stirring under reux, asolution consisting of 200 ml. of acetonitrile and 60 g. ofm-nitrophenyl isocyanate was added dropwise into the system. During theaddition, the pyrazolone Went into solution then the solution rapidlybegan to separate crystals. After stirring for 2 hours under reflux, theproduct was collected by filtration and was recrystallized from amixture of one part of dimethylformamide and two parts of ethanol togive 50 g. of the compound melting at 254 C.

(c) Reduction of the nitro group-While stirring under reflux the wholeamount of the nitro compound obtained above in 500 ml. of methanol, 500ml. of glacial acetic acid and 50 ml. of water, '50 g. of reduced ironpowder were added gradually. After 2 hours, the reaction mixture waspoured into 5 liters of hot water and was allowed to stand overnight.The product was collected by filtration and recrystallized from asolvent mixture of ethanol and acetonitrile (1:1) to give 30 g. of theamine melting at 207 C.

(d) 'Synthesis of Compound I.-A mixture of 15 g. of the amine obtainedin step (c), 4.5 g. of sodium acetate and 2160 ml. of glacial aceticacid was warmed to 50-60 C., while stirring and into the solution wasgradually added a solution of 14.5 g. of 2,4-di-t-amylphenoxyacetylchloride in 75 ml. of glacial acetic acid. The mixture'was allowed toreact for 2 hours at this temperature.

The reaction mixture was poured into 1.5 liters of cold water and theproduct was collected by iltration, dried and recrystallized from amixture of methanol and acetonitrile (1:1) to give 8 g. of Compound Imelting at 182 C.

Preparation of Compound II A mixture of g. of the amine obtained in step(c) in the preparation of Compound I, 4.5 of sodium acetate and 260 ml.of glacial acetic acid was warmed to 50-60 C. While stirring, a solutionof 14.5 g. of 2,4-di-sec-amylphenoxyacetyl chloride in 75 ml. of glacialacetic acid was added dropwise. The mixture was allowed to react for 2more hours at this temperature.

The reaction mixture was poured into 1.5 liters of cold Water and theproduct was collected by filtration, dried and recrystallized from amixture of acetone and methanol (1:1) to give 6 g. of Compound 1Imelting at 174 C.

Preparation of Compound IV (a) Synthesis of1-(2,4,6-trichlorophenyl)-3-(3-nitrophenylureido)-5pyrazolone.-In al-liter three-necked flask were placed 84 g. of1-(2,4,6-trichlorophenyl)-3- amino-S-pyrazolone (see U.S. Pat.2,600,788) and 600 ml. of anhydrous acetonitrile. While stirring underreflux, a solution consisting of 200 ml. of anhydrous acetonitrile and49 g. of m-nitrophenyl isocyanate was added gradually. After theaddition, the mixture became clear and after about 30 minutes began toseparate a large amount of crystals which were collected lby ltrationand washed with hot acetonitrile to give 40 g. of the nitro compoundmelting at 232 C.

(b) Reduction of the nitro compound.- The reduction of the nitrocompound was conducted in the same way as the preparation of Compound I.Thus, by reduction of 40 g. of the nitro compound obtained above, l5 g.of the amine melting at 224 C. was obtained.

(c) Synthesis of Compound IV.-In 240 ml. of glacial acetic acid weresuspended 15 g. of the amine obtained above, and 4.5 g. of sodiumacetate, and, while stirring at 50-50" C., a solution of 13 g. of2,4-di-t-amylphenoxyacetyl chloride and ml. of glacial acetic acid weregradually added dropwise into the suspension. After the addition, themixture was allowed to react for 2 more hours. The reaction mixture Waspoured into 1.5 liters of cold water. The product was collected and wasrecrystallized, after drying, from a solvent mixture of acetonitrile andmethanol (1:1) to give 9 g. of Compound IV melting at 198 C.

Preparation of Compound VI (a) Preparation of 1-(2-ethoxyphenyl) 3 samino-5- pyrazoline.-A mixture of 64 g. of o-ethoxyphenylhydrazine, 360ml. of methanol and 70 g. of anhydrous sodium acetate was cooled below10 C., and 90 g. of ethyl ethoxy--iminopropionate hydrochloride weregradually added. The resulting solution was stirred for minutes at roomtemperature.

Then, a sodium methylate solution prepared from 42 g. of sodium metaland 600 m1. of methanol maintained at 10 C. -Was added to the system.The solution was stirred for 90 more minutes at room temperature. Then,the reaction mixture was poured into 3 liters of cold Water. Afterneutralization with acetic acid, the product was extracted with ethylacetate and dried over anhydrous sodium sulfate. The solvent was removedunder reduced pressure and the remaining syrup was washed with hexaneand digested with ether until it crystallized. It was recrystallizedfrom ethyl acetate to give 64 g. of the pyrazolone melting at 166 C.

(b)y Preparation of 1 (2 ethoxyphenyl)3-(3nitro phenylureido)-5-pyrazolone.-By the reaction of 44 g. of the pyrazolone prepared abovewith 33 g. of m-nitrophenyl isocyanate in the same procedure as step (b)of the preparation of Compound I, 30 g. of the above compound melting at210 C. was obtained.

(c) Reduction of the nitro group-The whole amount of the nitro compoundprepared by step (b) was re- 1 1 duced as in step (c) of the preparationof Compound I. The product thus obtained was recrystallized from asolvent mixture of acetonitrile and ethanol (1:1) containing a smallamount of methyl Cellosolve to give 7.2 g. of the amine melting at 190C.

(d) Synthesis of Compound VI.-7.2 g. of the amine prepared above and 2g. of anhydrous sodium acetate were suspended in 100 ml. of glacialacetic acid and, while stirring, an acetic acid solution of 6.4 g. of2,4-dit-amylphenoxyacetyl chloride was added dropwise into thesuspension. After 2 hours, the reaction mixture was poured into coldwater. The product was collected by filtration, washed well with waterand dried to give 7 g. of Compound VI ymelting at 120 C.

Preparation of Compound IX (a) Preparation of1-(2,6-dichloro-4-methylpheny1)-3-(3-nitropheny1ureido)-5-pyrazolone.-In 700 ml. of acetonitrile weredissolved 100 g. of 1-(2,6-dichloro-4-methylphenyl)3amino-5pyrazoloneand while stirring under reflux, 64 g. of m-nitrophenyl isocyanatedissolved in 200 ml. of acetonitrile were added dropwise. After about 40minutes a large quantity of product precipitated. After 1.5 hours, theprecipitates were collected by filtration and washed with Ihotacetonitrile to give 110 g. of the nitro compound melting at 248 C.

The aminopyrazolone used here had been prepared by the reaction of2,6-dichloro-4-methylphenylhydrazine with ethyl-amino--ethoxy-propionate in a similar way as step (a) of thepreparation of Compound VI followed by recrystallization of the productfrom acetonitrile.

(b) Reduction of the nitro compound-In the mixture of 500 ml. ofmethanol, 500 ml. of glacial acetic acid and 50 ml. of water weresuspended 50 g. of the nitro compound obtained in step (a) and reducedwith iron powder according to step (c) of the preparation of Compound I.The product was recrystallized from the mixture of 2 parts of lmethanoland 1 part of acetonitrile to give 23 g. of the amino compound meltingat 225 C.

(c) Synthesis of Compound yIX.-In 360 g. of glacial acetic acid wereplaced 23 g. of the amine thus prepared and 6 g. of anhydrous sodiumacetate. A solution of 19.5 g. of 2,4-di-t-aminophenoxyacetyl chloridein 72 ml. of glacial acetic acid was added dropwise into the solutionwithin 10 minutes. After 2 hours, the mixture was poured into cold waterto precipitate the product, which was recrystallized from a mixture of 3parts of methanol and 2 parts of acetonitrile to give 10 g. of CompoundIX melting at 150 C.

Preparation of Compound X (a) Preparation of1-(2,6-dichloro-4-methoxyphenyl)3-(3-nitro-phenylureido)5-pyrazolone.-In 500 ml. of acetonitrile weretreated 40 g. of m-nitrophenyl isocyanate with 67 g. of1-(2,6-dichloro-4-methoxyphenyl)-3-amino- 5-pyrazolone, (see BritishPat. 904,852) according to step (b) of the preparation of Compound 1I togive 67 g. of the nitro compound melting at 227 C.

(b) Reduction of the nitro group-In a mixture of 670 m1. of methanol,670 ml. of glacial acetic acid and 67 rnl. of water were reduced 67 g.of the nitro compound obtained above by means of 67 g. of reduced ironpowder, and the product thus prepared was recrystallized from a mixtureof 3 parts of ethanol and 2 parts of dimethylformamide to provide 52 g.of the amine, melting at 200- 201 C.

(c) Synthesis of Compound X.-In 520 ml. of glacial acetic acid weresuspended 52 g. of the amino compound prepared in step (b) and 12.5 g.of anhydrous sodium acetate, and while stirring, 40 g. of2,4-di-t-amy1phenoxyacetyl chloride and 120 ml. of glacial acetic acidwere added dropwise into the suspension at 50-60" C. After 1 hour, themixture was poured into cold water to precipitate the product, which wascollected by filtration, dried,

and recrystallized from methanol to give 69 g. of the crystal ofCompound X melting at 139 C.

Preparation of Compound XIII-In 200 ml. of glacial acetic acid weresuspended l g. of the amine prepared by step (c) of the preparation ofCompound I and 2.5 g. of anhydrous sodium acetate and, while stirring at50-60 C., a solution of 8 g. of palmitoyl chloride in 50 ml. of glacialacetic acid was added dropwise into the suspension within minutes. After1 hour, the reaction mixture was poured into 1 liter of cold water. Theproduct was collected by filtration, dried and recrystallized twice froma mixture of methanol and acetonitrile (1:1) and once from ethanol togive 4 g. of Compound XIII melting at 178 C. Couplers described in thisapplication can be mixed with a small amount of cyanor yellow-formingcoupler to improve the color reproduction according to Japanese patentpublication No. 391/ 1965.

This invention can be satisfactorily applied to many types oflight-sensitive materials, for example, color-printing papers, positivecolor films, negative color films,

reversal color films and so forth.

Also this invention is expected to be applicable not only to so-calledmultilayer color photographic materials, but also to so-called mixedgrain type ones. The invention will further be explained by thefollowing examples.

EXAMPLE 1 A solution prepared by warming to 70 C. a mixture of l5 g. ofCompound I, 30 g. of di-n-butyl phthalate and 20 ml. of butyl acetatewas added to 300 ml. of an aqueous solution of 1.0 g. of sodiumdodecylbenzenesulfonate and 25 g. of gelatin. The mixture was stirredfor 30 minutes in a homogenizer, and the whole amount of the mixture wasmixed with 500 g. of a green-sensitive photographic emulsion.

After addition of 30 ml. of a 3% acetone solution oftriethylene-phosphoramide and adjustment of the pH to 7.0, the resultingcomposition was applied to cellulose triacetate film to a dry-thicknessof 5.0 104 cm.

The coating contained 5.8% X 10-3 mole of silver iodobromide and7.2)(10-4 mole of the coupler per square meter. The lm was exposed andsubjected to the following processing steps to yield a clear magentaimage with an absorption maximum at 551 mit. The spectral absorptioncurve has been shown in FIG. 1 by curve a.

COLO R DEVELOPMENT PROCESSES Tempera- Period,

Step ture, C. minutes Color development 21 10 Rinsing 21 1 First fixing21 4 Rinsing 21 3 Bleaching.. 21 3 Rinsing.. 21 2 Second fixing-. 21 3 55 Washing 18 20 The compositions used in the above processes are asfollows Boric acid- 10 g. Borax--S g. Potassium ybromide---7 g.

EXAMPLE 2 A solution prepared by warming to 70 C. a mixture of l g. ofCompound X, 30 g. of tricresyl phosphate, and 10 ml. of ethyl acetatewas added to 100 ml. of an aqueous Solution containing 0.5 g. of sodiumdodecyl sulfate and 7 g. of gelatin at 60 C., and the resulting mixturewas stirred vigorously by means of an homogenizer to disperse thecoupler nely together with the solvent.

The Whole amount of the emulsion thus obtained was added to 540 g. of agreen-sensitive photographic emulsion. After addition of 30 ml. of 3%acetone solution of triethylenephosphoramide as a hardening agent and 7g. of polyvinyl pyrrolidone, the resulting composition was applied tobaryta paper as the middle layer to a dry-thickness of 4 104 cm. Itsbottom layer was a` blue-sensitive photographic emulsion layercontaining an emulsifed dispersion of coupler (L) having the followingstructure. On the middle layer thus formed was coated as the top layer ared-sensitive emulsion containing an emulsied dispersion of coupler (M)shown below.

(EO O 0121125 CH3 Cl l @commune EXAMPLE 3 A mixture of 6 g. of CompoundIX and 18 g. of dibutyl phthalate was warmed to 80 C., and added to 50ml. of an aqueous solution containing 5 g. of gelatin and 0.3 g. ofsodium dodecylbenzenesulfonate, and the resulting mixture was stirredvigorously by means of an homogenizer to prepare an emulsied dispersion.

The whole amount of the coupler-containing emulsied dispersion was mixedwith 200 g. of a photographic emulsion. After addition of ml. of a 3%acetone solution of triethylene phosphoramide as a hardening agent, themixture was applied to a cellulose triacetate film to a dry-thickness of6 10f4 cm. and dried. In this case, the coating contained 7.2X104 molcoupler and 5.8X10f3 mol silver iodobromide per square meter. The filmwas exposed to graduated intensities of light with aid of a sensitometerand developed for 6 minutes at 24 C. in a developer of the followingcomposition and then washed with water for l5 minutes at the sametemperature; then it was exposed uniformly to white light andcolordeveloped as described in Example 1.

Black and white developer (pH 10.8):

Water-1,000 ml. Metol-3 g. Sodium sulite (anhydrous)-5O g. Sodiumcarbonate, monohydrate-lOO g. Potassium thiocyanate3.6 g. Potassiumbromide-2 g.

The reversal magenta color image thus obtained had an absorption maximumat 554 mp.. The spectral absorption curve has been shown in FIG. 3 ofthe attached drawing as curve e.

EXAMPLE 4 Two films (P) and (Q) were prepared as follows:

Film (P).-A solution prepared by heating to 70 C. a mixture of 15 g. ofCompound IV, 30 g. of tricresyl phosphate and 20 ml. of butyl acetatewas mixed with 300 ml. of an aqueous solution containing 25 g. ofgelatin and 1.0 g. of sodium dodecylbenzenesulfonate. The mixture Wasstirred for 30 minutes by means of a homoblender to disperse thecoupler. The whole amount of the dispersion was mixed with 500 g. ofphotographic emulsion. After addition of 30 m1. of 3% acetone solutionof trethylenephosphoramide as a hardening agent, the mixture wasneutralized to pH 7.0 and was applied to a cellulose triacetate film toa dry-thickness of 5.0X10-4 cm. The coating contained 7.2 10*4 molcoupler and 5.8)(10-3 mol silver iodobromide per square meter.

Film (Q).-A similar procedure to the preparation of Film (P) wasrepeated using Compound B (control) instead of Compound IV.

The films were exposed to graduated intensities of light by means of asensitometer and processed in the same manner as Example 1. Theirphotographic properties are as follows:

Sensitivity Maximum Sample Coupler Fog (relative) Gamma density Film PIV 0.09 2.20 3.05 Film Q B 0. 08 100 1. 61 2. 16

The fastness of the color image was tested, and the results are shown inthe following table:

(B), (A),initial increase (C),initial (D), initial NOTE: (A) Fading(percent) by light (after 40 hours, exposure in a xenon tester) (B)Coloring of uncoupled portion by light (after 40 hours, exposure in axenon tester), (C) Fading (percent) at a high temperature and a highhumidity (60 C. 75% RH for 20 days), and (D) Fading (percent) by heat(at 120 C., for 4 hours).

From the above results, it is clear that Film (P), (Coupler IV)according to the present invention, gives a high sensitivity, a highgamma and a high maximum density compared with those of Film Qcontaining the conventional coupler (B), and that the color image0btained is markedly fast to light, heat and humidity. Moreover, evenintense radiation did not cause yellowing due to the remaining coupler.

The spectral absorption curve of the color image formed by Compound IVhas been shown in FIG. 2 of the attached drawing by curve c.

What is claimed is:

1. A color photographic silver halide emulsion containing at least onemagenta coupler of the formula wherein RCO represents an acyl grouphaving from 18 to 25 carbon atoms and Ar represents a phenyl grouphaving at least one substituent at the ortho position, the substituentbeing one selected from the group consisting of halogens, alkyl groupsand alkoxyl groups.

2. A color photographic silver halide emulsion as delined in claim 1where the compound is:

tert. cmu-@ oomooNH@ l tort. 05H11 NHCONH-C-OHg 3. A color photographicsilver halide emulsion as dened in claim 1 where the compound is:

sec. @LIQ-H20 ONE@ NHG ONH-C--CHz 4. A color photographic silver halideemulsion as dened in claim 1 Where the compound is:

CusHsxC 0 )NoHzcHzooNH-Q 5. A color photographic silver halide emulsionas dened in claim 1 where the compound is:

tert. 05H11- -OCHaCONH tert. 05H11 NHG ONH-IC- CH2 Cl- -Cl 6. A colorphotographic silver halide emulsion as dened in claim 1 where thecompound is:

@-00150 ONE@ SBC. 05H11- sec. 05H11 NHCONH-C--Clh N C=O Cl- -Cl 7. A acolor photographic silver halide emulsion as defined in claim 1 wherethe compound is:

@-oouzoomr@ tert. 05H11 NHCONH-C-CHz N C=O 8. A color photographicsilver halide emulsion as delined in claim 1 where the compound is:

9. A color photographic silver halide emulsion as defined in claim 1where the compound is:

10. A color photographic silver halide emulsion as dened in claim 1where the compound is:

17 18 11. A color photographic silver halide emulsion as 13. A colorphotographic silver halide emulsion as defined in claim 1 where thecompound is: defined in claim 1 where the compound is:

l o oHCoNH-Q terr.. cmu-Q-oomoolm-Q l meenam NHooNn-c-om N :0

o=o N o1 o1- c1 on a" l 14. A color photographic silver halide emulsionas I O CHS defined in claim 1 where the compound is:

owHuooNH-Q l 12. A color photographic silver halide emulsion asNHCONH-|3-(|JH2 defined in claim 1 where the compound is: N /C=0nernoHuQ-oomooNH-Q C1 terLCsHu llIHooNH-C--CH C|=0 30 \N/ ReferencesCited l UNITED STATES PATENTS C1' CH 3,393,071 7/1968 Monbaliu et a1.96-100 3,462,270 8/1969 Eynde et al 96-100 H J. TRAVIS BROWN, PrimaryExaminer U.S. Cl. X.R. 96-74; 260-310

